164 Si r Everard Home on the canal for containing , &c. 
EXPLANATION OF THE PLATES. 
PLATE XV. 
This Plate consists of two figures, representing portions of 
the skull, jaw, and other parts, of the natural size. 
Fig. 1 . A portion of the skull behind the orbit. The two 
principal objects in this figure are, the mode of articulation 
of the spinous processes with the bodies of the vertebras of 
the back, forming the canal in which the spinal marrow is 
contained ; and the fin of this animal in the most perfect 
state yet discovered, one hundred and seventy separate bones 
remaining in their natural situation. 
Fig. 2. Shows the anterior portions of both jaws, which 
appear from their size to have belonged to the same skull as 
Fig. l, having been found in the same situation; allowance 
must however be made, for a considerable intervening por- 
tion having been lost. 
PLATE XVI. 
Represents a transverse section of the nasal bones, of the 
natural size. 
This is the only opportunity that has offered of seeing the 
cavity of the nostrils. 
The teeth and their sockets in both jaws were accidentally 
divided in making the section of the nose, and their internal 
structure exposed, from which it appears, that the mode of 
growth is similar to that of the crocodile ; the succeeding 
tooth filling up the cavity of that which preceded it. 
